1)(2 7/30-3 1/5*7/12)*7 1/2 2) (6 3/8-5 7/12)*5 1/7-6/73) 7*(1/12+1/18)*(1 3/5-4/7)

1) ((2 * 30 + 7)/30 - (3 * 5 + 1)/5 * 7/12) * (7 * 2 + 1)/2 = (67/30 - 16/5 * 7/12) * 15/2 = (134/60 - 112/60) * 15/2 = 22/60 * 15/2 = (22 * 15)/(60 * 2) = 11/4;

Ответ: 11/4.

2) ((6 * 8 + 3)/8 - (5 * 12 + 7)/12) * (5 * 7 + 1)/7 - 6/73) * 7 * (1/12 + 1/18) * ((1 * 5 + 3)/5 - 4/7) = (51/8 - 67/12) * 36/7 - 6/73) * 7 * (3/36 + 2/36) * (8/5 - 4/7) = ((153/24 - 134/24) * 36/7 - 6/73) * 7 * 5/36 * (56/35 - 20/35) = (19/24 * 36/7 - 6/73) * 35/36 * 36/35 = 19/4 * 6/7 - 6/73 = 57/14 - 6/73 = (4161 - 84)/1022 = 4077/1022.

Ответ: 4077/1022.

https://znanija.com/task/43773054